Hermeus Quarterhorse Mk 2.1 Achieves First Unmanned Supersonic Flight
© 2026 New Atlas
Menu
Show Search
Search Query<br>Submit Search
TECH
ENGINEERING
OUTDOOR
TRANSPORT
SCIENCE & HEALTH
SUBSCRIBE
HOME
Aircraft
SR-71 successor? Quarterhorse Mk 2.1 prototype cracks the sound barrier
By David Szondy
May 28, 2026
SR-71 successor? Quarterhorse Mk 2.1 prototype cracks the sound barrier
The Quarterhorse Mark 2.1<br>Hermeus
View 2 Images
1/2
The Quarterhorse Mk 2.1 taking off<br>Hermeus
2/2
The Quarterhorse Mark 2.1<br>Hermeus
The venerable Cold War SR-71 Blackbird may be looking nervously at its laurels after Hermeus's latest Quarterhorse Mk 2.1 uncrewed prototype broke the sound barrier at Spaceport America over the White Sands Missile Range airspace in New Mexico in March 2026.<br>To this day, the Lockheed SR-71 Blackbird holds a number of air records, including the official world airspeed record for a crewed, air-breathing jet aircraft when it reached Mach 3.32 in 1976; the absolute altitude record for sustained horizontal flight; and speed over a closed 1,000-km (621-mile) course. Added to this, it also set time-and-distance records for flights between New York and London; London and Los Angeles; Los Angeles and Washington, DC; Kansas City and Washington, DC; and St. Louis and Cincinnati.<br>Not only could the high-altitude spy plane set such records, it could cruise at high supersonic speeds as a matter of routine while gathering intelligence for the US and NATO, all while reportedly outrunning more than 4,000 anti-aircraft missiles during its operational career.
Quarterhorse 2.1
The Blackbirds were retired to museums three decades ago, but their legacy lives on as both an example and a challenge to modern aerospace engineers. Though it's uncrewed, Hermeus sees its Quarterhorse project as both the spiritual and technological successor to the SR-71.<br>The goal of the project is not only to build an aircraft capable of surpassing the Blackbird's records, but also to act as a testbed for critical technologies needed for routine, sustained hypersonic flight. These include the company's Chimera turbine-based combined-cycle (TBCC) propulsion system, which integrates a conventional turbojet engine with a ramjet to enable transitions from subsonic to hypersonic speeds.<br>Hermeus's approach isn't to build a single airframe. Instead, its engineers have opted for rapid prototyping by building a series of aircraft, each designed to handle a specific phase of development – from taxi tests to takeoff and landing, and now supersonic flight – before eventually taking on the legacy of the SR-71.
The Quarterhorse Mk 2.1 taking offHermeus
The latest flight of the F-16 Fighting Falcon-sized Mk 2.1 took place 364 days after the maiden flight of the Quarthorse Mk 1, reaching a top speed of Mach 1.21. According to the company, data collected from the current tests will be used to develop the Mk 2.2 and Mk 2.3, moving toward sustained high-supersonic flight with the uncrewed Darkhorse multi-mission military aircraft and, ultimately, the Halcyon, a 20-passenger commercial hypersonic transport jet.<br>"Our customers at the Department of War are paying close attention to how fast this program is moving," said AJ Piplica, CEO and Co-founder of Hermeus. "This flight demonstrates a pace of execution that is extremely rare in modern aviation. Our country’s ability to deliver new asymmetric military capability at scale depends on teams that can solve hard technical challenges quickly. That’s exactly what we’re proving with each test flight we conduct and each new aircraft we build at Hermeus."<br>Source: Hermeus
Tags
AircraftAircraftSupersonicHermeusSR-71
3 comments
David Szondy
David Szondy is a playwright, author and journalist based in Seattle, Washington. A retired field archaeologist and university lecturer, he has a background in the history of science, technology, and medicine with a particular emphasis on aerospace, military, and cybernetic subjects. In addition, he is the author of four award-winning plays, a novel, reviews, and a plethora of scholarly works ranging from industrial archaeology to law. David has worked as a feature writer for many international magazines and has been a feature writer for New Atlas since 2011.
Sign up for our FREE daily New Atlas newsletter !
More stories like this:
Aircraft
Quarterhorse 2.1 takes flight on way to beating 50-year-old SR-71 record
Aerospace startup Hermeus has taken another step toward challenging the Lockheed SR-71 Blackbird’s legendary supersonic speed record as the company’s uncrewed Quarterhorse Mk 2.1 lifted off from Spaceport America in New Mexico on March 2, 2026 for its maiden flight.
Aircraft
Australia launches 3D-printed, Mach 8 hypersonic missile from US soil
Australia's Hypersonix Launch Systems has made a historic launch of its next-generation DART...